On Autism's Cause, It's Parents vs. Research

By GARDINER HARRIS and ANAHAD O'CONNOR

Published: June 25, 2005

CORRECTION APPENDED

Kristen Ehresmann, a Minnesota Department of Health official, had just told a State Senate hearing that vaccines with microscopic amounts of mercury were safe. Libby Rupp, a mother of a 3-year-old girl with autism, was incredulous.

''How did my daughter get so much mercury in her?'' Ms. Rupp asked Ms. Ehresmann after her testimony.

''Fish?'' Ms. Ehresmann suggested.

''She never eats it,'' Ms. Rupp answered.

''Do you drink tap water?''

''It's all filtered.''

''Well, do you breathe the air?'' Ms. Ehresmann asked, with a resigned smile. Several parents looked angrily at Ms. Ehresmann, who left.

Public health officials like Ms. Ehresmann, who herself has a son with autism, have been trying for years to convince parents like Ms. Rupp that there is no link between thimerosal -- a mercury-containing preservative once used routinely in vaccines -- and autism.

They have failed.

The Centers for Disease Control and Prevention, the Food and Drug Administration, the Institute of Medicine, the World Health Organization and the American Academy of Pediatrics have all largely dismissed the notion that thimerosal causes or contributes to autism. Five major studies have found no link.

Yet despite all evidence to the contrary, the number of parents who blame thimerosal for their children's autism has only increased. And in recent months, these parents have used their numbers, their passion and their organizing skills to become a potent national force. The issue has become one of the most fractious and divisive in pediatric medicine.

''This is like nothing I've ever seen before,'' Dr. Melinda Wharton, deputy director of the National Immunization Program, told a gathering of immunization officials in Washington in March. ''It's an era where it appears that science isn't enough.''

Parents have filed more than 4,800 lawsuits -- 200 from February to April alone -- pushed for state and federal legislation banning thimerosal and taken out full-page advertisements in major newspapers. They have also gained the support of politicians, including Senator Joseph I. Lieberman, Democrat of Connecticut, and Representatives Dan Burton, Republican of Indiana, and Dave Weldon, Republican of Florida. And Robert F. Kennedy Jr. wrote an article in the June 16 issue of Rolling Stone magazine arguing that most studies of the issue are flawed and that public health officials are conspiring with drug makers to cover up the damage caused by thimerosal.

''We're not looking like a fringe group anymore,'' said Becky Lourey, a Minnesota state senator and a sponsor of a proposed thimerosal ban. Such a ban passed the New York State Legislature this week.

But scientists and public health officials say they are alarmed by the surge of attention to an idea without scientific merit. The anti-thimerosal campaign, they say, is causing some parents to stay away from vaccines, placing their children at risk for illnesses like measles and polio.

''It's really terrifying, the scientific illiteracy that supports these suspicions,'' said Dr. Marie McCormick, chairwoman of an Institute of Medicine panel that examined the controversy in February 2004.

Experts say they are also concerned about a raft of unproven, costly and potentially harmful treatments -- including strict diets, supplements and a detoxifying technique called chelation -- that are being sold for tens of thousands of dollars to desperate parents of autistic children as a cure for ''mercury poisoning.''

In one case, a doctor forced children to sit in a 160-degree sauna, swallow 60 to 70 supplements a day and have so much blood drawn that one child passed out.

Hundreds of doctors list their names on a Web site endorsing chelation to treat autism, even though experts say that no evidence supports its use with that disorder. The treatment carries risks of liver and kidney damage, skin rashes and nutritional deficiencies, they say.

In recent months, the fight over thimerosal has become even more bitter. In response to a barrage of threatening letters and phone calls, the centers for disease control has increased security and instructed employees on safety issues, including how to respond if pies are thrown in their faces. One vaccine expert at the centers wrote in an internal e-mail message that she felt safer working at a malaria field station in Kenya than she did at the agency's offices in Atlanta.

An Alarm Is Sounded

Thimerosal was for decades the favored preservative for use in vaccines. By weight, it is about 50 percent ethyl mercury, a form of mercury most scientists consider to be less toxic than methyl mercury, the type found in fish. The amount of ethyl mercury included in each childhood vaccine was once roughly equal to the amount of methyl mercury found in the average tuna sandwich.

In 1999, a Food and Drug Administration scientist added up all the mercury that American infants got with a full immunization schedule and concluded that the amount exceeded a government guideline. Some health authorities counseled no action, because there was no evidence that thimerosal at the doses given was harmful and removing it might cause alarm. Others were not so certain that thimerosal was harmless.

Correction: July 20, 2005, Wednesday
A front-page article on June 25 about a debate over whether autism is caused by thimerosal, a mercury-containing preservative once routinely used in vaccines, misattributed a statement that was part of an exchange in which a parent of an autistic child asked officials of the Minnesota Department of Health, ''How did my daughter get so much mercury in her?'' The final statement in the exchange, ''Well, do you breathe the air?,'' was made by Patricia Segal-Freeman of the Health Department, not her colleague Kristen Ehresmann. (When read a transcript before publication, Ms. Ehresmann confirmed that she was the speaker in the exchange; she later acknowledged that the statement was made by Ms. Segal-Freeman.)

Because of an editing error, the article also misspelled the given name of the president of SafeMinds, one of several groups that argue that there is a link between thimerosal and autism. She is Lyn Redwood, not Lynn.